EVALUATION OF CHARACTERISTIC IMPEDANCE OF TWIN-WIRE TRANSMISSION-LINEINSULATED BY MULTILAYER DIELECTRIC

A method is presented of finding the characteristic impedance of twin- cylinder transmission line, each of which is covered by multilayer die lectric based on conformal transformation. Cotangent hyperbolic transf ormation is used to transform the cross-sections of the metallic bound aries to parallel plates and dielectric boundaries to curved contours. The curved contours are replaced by a large number of discrete steps and the capacitance per unit length of the structure is found from a s eries and parallel combination of infinitesimal capacitances. The char acteristic impedance is found from the capacitance per unit length. Nu merical results on capacitance per unit length and characteristic impe dance are presented.